A method of 3d interlocking graphene interface toughened ceramic

Abstract

The application discloses a method for preparing 3D interlocking graphene interface strong and tough ceramic, which comprises the following steps: growing vertical graphene on the surface of ceramic powder in situ by using methanol as a precursor through a low-pressure chemical vapor deposition method, realizing uniform and large-area coverage of the graphene on the surface of the ceramic powder, and obtaining composite ceramic powder with the vertical graphene deposited thereon; and performing hot-pressing sintering on the composite ceramic powder with the vertical graphene deposited thereon, so as to obtain 3D interlocking graphene interface strong and tough composite ceramic. The method can enhance the weak shear resistance between graphene layers.

Description

Technical Field

[0001] This invention belongs to the field of materials preparation and relates to a method for developing a 3D interlocked graphene interface tough ceramic. Background Technology

[0002] Graphene has been highly sought after since its discovery. Its two-dimensional planar crystal structure, when used as a strong and tough phase in ceramic materials, allows it to generate numerous interfaces and improve interfacial bonding, offering significant advantages in stress transmission. (C's sp) 2 Hybrid bonds endow graphene with extremely high in-plane elastic modulus and tensile strength. However, its interlayers are only connected by hydrogen bonds and van der Waals forces, making them prone to slippage or even direct fracture. Therefore, new methods are needed to further enhance the weak interlayer shear resistance of graphene. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for strengthening 3D interlocked graphene interface ceramics, which can enhance the weak shear resistance between graphene layers.

[0004] To achieve the above objectives, this invention discloses a method for strengthening and toughening 3D interlocked graphene interfaces in ceramics, comprising:

[0005] A composite ceramic powder with vertically deposited graphene was obtained, and the composite ceramic powder with vertically deposited graphene was hot-pressed and sintered to obtain a 3D interlocked graphene interface with strong and tough composite ceramic.

[0006] Specifically, the following steps are included:

[0007] The composite ceramic powder with vertically deposited graphene was pre-cooled and pressed in a graphite sleeve, then vacuum hot-pressed and sintered, and then cooled to room temperature in the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0008] The pre-cooling time is 10 min to 30 min; the cold pressing pressure is 20% to 50% of the hot pressing pressure.

[0009] The sintering temperature is 1550℃~2000℃, and the holding time is 5min~2h.

[0010] The heating rate during the hot pressing process is 5℃ / min to 50℃ / min, and the hot pressing pressure is 20MPa to 80MPa.

[0011] The process of obtaining composite ceramic powder with deposited vertical graphene is as follows:

[0012] Using methanol (CH3OH) as a precursor, vertical graphene is grown in situ on the surface of ceramic powder by low-pressure chemical vapor deposition (CVD), achieving uniform and large-area coverage of graphene on the surface of ceramic powder, and obtaining composite ceramic powder with deposited vertical graphene.

[0013] The specific process for obtaining the composite ceramic powder with deposited vertical graphene is as follows:

[0014] 1) Place the ceramic powder in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat it to 900℃~1200℃.

[0015] 2) Introduce CH3OH to maintain the temperature and deposit graphene. After the deposition is completed, stop supplying CH3OH and cool down. Maintain a low-pressure atmosphere throughout the process to obtain composite ceramic powder with vertically deposited graphene.

[0016] In step 1), the ceramic powder has a spherical morphology and an average particle size of 0.1 μm to 20 μm.

[0017] The deposition time for graphene is 1 hour to 10 hours.

[0018] The amount of powder fed during the deposition process is 1g to 15g.

[0019] The present invention has the following beneficial effects:

[0020] The method for strengthening ceramics with 3D interlocked graphene interfaces described in this invention involves selecting structurally unique vertical graphene as the strengthening phase, and then hot-pressing and sintering it to obtain a 3D interlocked graphene interface with reinforced interlayer strength. This efficiently strengthens and toughens the matrix material, enhancing the weak shear resistance of the graphene interlayers. It should be noted that vertically oriented graphene is multi-oriented graphene grown on the basis of parallel graphene, possessing abundant exposed active edges. Under suitable conditions, it can spontaneously stitch together to form a 3D interlocked graphene interface, thereby strengthening both the interlayer and intralayer strength of the graphene.

[0021] Furthermore, this invention employs low-pressure chemical vapor deposition (CVD) to grow vertically oriented graphene in situ on the surface of ceramic powder, thereby obtaining composite ceramic powder with deposited vertically oriented graphene. This fundamentally solves the problem of graphene agglomeration, achieving high coverage and uniform distribution of graphene over the matrix material. It not only establishes a continuous, strong graphene network but also confines and refines ceramic grains. In practical operation, the structure and morphology of graphene can be controlled by adjusting parameters such as temperature and time during the CVD process to achieve different strength and toughness effects, demonstrating significant potential for wide-temperature-range applications. Attached Figure Description

[0022] Figure 1aScanning electron micrograph of alumina (Al2O3) powder;

[0023] Figure 1b Transmission electron micrograph of Al2O3 powder (G-Al2O3) in which graphene was grown in situ by CVD.

[0024] Figure 2 The image shows the interface morphology of graphene and alumina in sintered graphene-reinforced alumina ceramic (G / Al2O3).

[0025] Figure 3 The graph shows the flexural strength test results of pure Al2O3 ceramic and G / Al2O3 ceramic after sintering.

[0026] Figure 4 The figure shows the fracture toughness test results of pure Al2O3 ceramic and G / Al2O3 ceramic after sintering. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are not intended to limit the scope of the present invention. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion regarding the concepts disclosed in the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0028] The accompanying drawings show structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0029] The principle of the method for producing 3D interlocked graphene interface strong and tough ceramics according to the present invention is as follows: using methanol as a precursor, vertical graphene is grown in situ on the surface of ceramic powder by low-pressure chemical vapor deposition to achieve uniform and large-area coverage of graphene on the surface of ceramic powder. Then, the composite ceramic powder with vertical graphene deposited is hot-pressed and sintered to obtain 3D interlocked graphene interface strong and tough composite ceramics.

[0030] Specifically, the method for strengthening 3D interlocked graphene interface ceramics according to the present invention includes the following steps:

[0031] 1) Place the ceramic powder in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat it to 900℃~1200℃.

[0032] 2) CH3OH is introduced to maintain the temperature and deposit graphene. After the deposition is completed, the supply of CH3OH is stopped and the temperature is lowered. The low-pressure atmosphere is maintained throughout the process to obtain composite ceramic powder with vertically deposited graphene.

[0033] 3) The graphene-ceramic powder is loaded into a graphite sleeve and pre-cooled for 10 min to 30 min at a pressure of 20% to 50% of the hot pressing pressure. Then, vacuum hot pressing sintering is performed. The sintering temperature is 1550℃ to 2000℃, the sintering time is 5 min to 2 h, the hot pressing pressure is 20 MPa to 80 MPa, and the heating rate is 5℃ / min to 50℃ / min. Then, the powder is cooled to room temperature in the furnace.

[0034] In this embodiment, the CH3OH is analytical grade.

[0035] In this embodiment, the ceramic powder has a spherical morphology and the best effect is achieved when the average particle size is 0.1μm to 20μm. In order to obtain the best strength and toughness effect, the graphene deposition time, pressure and sintering process are different for ceramic powders with different particle sizes.

[0036] In this embodiment, when the graphene deposition time is 1h to 10h and the deposition pressure is 8kPa to 20kPa, it exhibits a vertical morphology and optimal strength and toughness, corresponding to a graphene content percentage of 0.1% to 5%.

[0037] In this embodiment, to achieve a high coverage rate of graphene over ceramic powder, the deposition effect is best when the powder feeding amount per furnace is controlled between 1g and 15g.

[0038] Example 1

[0039] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0040] 1) Place Al2O3 ceramic powder with an average particle size of 0.2μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1050℃.

[0041] 2) CH3OH was introduced and kept at a temperature for 0.5 h to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0042] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 30 min, and then vacuum hot-pressed and sintered. The heating rate is 30℃ / min, the sintering temperature is 1800℃, the sintering time is 0.5 h, and the sintering pressure is 60 MPa. Then, it is cooled to room temperature in the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0043] In this embodiment, the CH3OH is analytical grade.

[0044] In this embodiment, the amount of powder fed per furnace is controlled at 15g.

[0045] Example 2

[0046] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0047] 1) Place Al2O3 ceramic powder with an average particle size of 0.2μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1100℃.

[0048] 2) CH3OH was introduced and kept at a temperature for 1 hour to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0049] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 30 min, and then vacuum hot-pressed and sintered. The heating rate is 20℃ / min, the sintering temperature is 1800℃, the sintering time is 1 h, and the sintering pressure is 50 MPa. Then it is cooled to room temperature with the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0050] In this embodiment, the CH3OH is analytical grade.

[0051] In this embodiment, the amount of powder fed per furnace is controlled at 5g.

[0052] Example 3

[0053] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0054] 1) Place Al2O3 ceramic powder with an average particle size of 0.5μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 980℃.

[0055] 2) CH3OH was introduced and kept at a temperature for 1 hour to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0056] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 25 min, and then vacuum hot-pressed and sintered. The heating rate is 30℃ / min, the sintering temperature is 1700℃, the sintering time is 1 h, and the sintering pressure is 50 MPa. Then it is cooled to room temperature with the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0057] In this embodiment, the CH3OH is analytical grade.

[0058] In this embodiment, the amount of powder fed per furnace is controlled at 10g.

[0059] Example 4

[0060] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0061] 1) Place Al2O3 ceramic powder with an average particle size of 0.5μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1080℃.

[0062] 2) CH3OH was introduced and kept at a temperature for 2 hours to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0063] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 25 min, and then vacuum hot-pressed and sintered. The heating rate is 10℃ / min, the sintering temperature is 1700℃, the sintering time is 2 h, and the sintering pressure is 80 MPa. Then it is cooled to room temperature with the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0064] In this embodiment, the CH3OH is analytical grade.

[0065] In this embodiment, the amount of powder fed per furnace is controlled at 10g.

[0066] Example 5

[0067] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0068] 1) Place Al2O3 ceramic powder with an average particle size of 1μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1100℃.

[0069] 2) CH3OH was introduced and kept at a temperature for 4 hours to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0070] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 20 min, and then vacuum hot-pressed and sintered. The heating rate is 10℃ / min, the sintering temperature is 1600℃, the sintering time is 2 h, and the sintering pressure is 30 MPa. Then it is cooled to room temperature with the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0071] In this embodiment, the CH3OH is analytical grade.

[0072] In this embodiment, the amount of powder fed per furnace is controlled at 10g.

[0073] Example 6

[0074] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0075] 1) Place Al2O3 ceramic powder with an average particle size of 1μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1140℃.

[0076] 2) CH3OH was introduced and kept at a temperature for 3 hours to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0077] 3) The graphene-Al2O3 powder was pre-cooled and pressed in a graphite sleeve for 20 min, and then vacuum hot-pressed and sintered. The heating rate was 10℃ / min, the sintering temperature was 1600℃, the sintering time was 0.5 h, and the sintering pressure was 60 MPa. Then the furnace was cooled to room temperature to obtain a 3D interlocked graphene interface strong composite ceramic.

[0078] In this embodiment, the CH3OH is analytical grade.

[0079] In this embodiment, the amount of powder fed per furnace is controlled at 10g.

[0080] Example 7

[0081] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0082] 1) Place Al2O3 ceramic powder with an average particle size of 3μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1090℃.

[0083] 2) CH3OH was introduced and kept at a temperature for 3 hours to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0084] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 20 min, and then vacuum hot-pressed and sintered. The heating rate is 20℃ / min, the sintering temperature is 1600℃, the sintering time is 1 h, and the sintering pressure is 40 MPa. Then it is cooled to room temperature with the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0085] In this embodiment, the CH3OH is analytical grade.

[0086] In this embodiment, the amount of powder fed per furnace is controlled at 15g.

[0087] Example 8

[0088] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0089] 1) Place Al2O3 ceramic powder with an average particle size of 3μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1100℃.

[0090] 2) CH3OH was introduced and kept at a temperature for 4 hours to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0091] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 20 min, and then vacuum hot-pressed and sintered. The heating rate is 10℃ / min, the sintering temperature is 1650℃, the sintering time is 2 h, and the sintering pressure is 35 MPa. Then it is cooled to room temperature with the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0092] In this embodiment, the CH3OH is analytical grade.

[0093] In this embodiment, the amount of powder fed per furnace is controlled at 10g.

[0094] Example 9

[0095] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0096] 1) Place Al2O3 ceramic powder with an average particle size of 5μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1140℃.

[0097] 2) CH3OH was introduced and kept at a temperature for 5 hours to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0098] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 15 min, and then vacuum hot-pressed and sintered. The heating rate is 10℃ / min, the sintering temperature is 1500℃, the sintering time is 0.5 h, and the sintering pressure is 50 MPa. Then, it is cooled to room temperature in the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0099] In this embodiment, the CH3OH is analytical grade.

[0100] In this embodiment, the amount of powder fed per furnace is controlled at 10g.

[0101] Example 10

[0102] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0103] 1) Place Al2O3 ceramic powder with an average particle size of 10μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1140℃.

[0104] 2) CH3OH was introduced and kept at a temperature for 5.5 h to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0105] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 15 min, and then vacuum hot-pressed and sintered. The heating rate is 30℃ / min, the sintering temperature is 1550℃, the sintering time is 0.5 h, and the sintering pressure is 30 MPa. Then it is cooled to room temperature in the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0106] In this embodiment, the CH3OH is analytical grade.

[0107] In this embodiment, the amount of powder fed per furnace is controlled at 15g.

[0108] Example 11

[0109] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0110] 1) Place Al2O3 ceramic powder with an average particle size of 15μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1150℃.

[0111] 2) CH3OH was introduced and kept at a temperature for 6 hours to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0112] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 10 min, and then vacuum hot-pressed and sintered. The heating rate is 20℃ / min, the sintering temperature is 1600℃, the sintering time is 2 h, and the sintering pressure is 35 MPa. Then it is cooled to room temperature with the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0113] In this embodiment, the CH3OH is analytical grade.

[0114] In this embodiment, the amount of powder fed per furnace is controlled at 5g.

[0115] Example 12

[0116] The method for producing 3D interlocked graphene interface-strengthened ceramics according to the present invention includes the following steps:

[0117] 1) Place Al2O3 ceramic powder with an average particle size of 20μm in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat to 1180℃.

[0118] 2) CH3OH was introduced and kept at a temperature for 8 hours to deposit graphene. After the deposition was completed, the supply of CH3OH was stopped and the temperature was lowered. The low-pressure atmosphere was maintained throughout the process to obtain graphene-Al2O3 ceramic powder with vertical morphology.

[0119] 3) The graphene-Al2O3 powder is pre-cooled and pressed in a graphite sleeve for 10 min, and then vacuum hot-pressed and sintered. The heating rate is 20℃ / min, the sintering temperature is 1600℃, the sintering time is 2 h, and the sintering pressure is 30 MPa. Then it is cooled to room temperature with the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

[0120] In this embodiment, the CH3OH is analytical grade.

[0121] In this embodiment, the amount of powder fed per furnace is controlled at 10g.

[0122] Table 1 shows the graphene preparation process and sintering parameters corresponding to the best strength and toughness of ceramic powders with different particle sizes. By adjusting the pressure and time during the deposition process, graphene with high coverage and vertical morphology can be obtained on the surface of ceramic powders with different particle sizes, which provides a guarantee for further preparation of cross-linked graphene networks. In addition, the sintering process is different for ceramic powders with different particle sizes. By adjusting the sintering parameters, the degree of cross-linking of graphene can be optimized.

[0123] Table 1

[0124]

[0125]

[0126] Figure 1a Scanning electron micrograph of alumina powder; Figure 1b This is a transmission electron micrograph of Al2O3 powder in situ grown with graphene by CVD. The average particle size of the Al2O3 powder is 1 μm, and its morphology is regular spherical. After 4 h of deposition, the surface of Al2O3 is covered with a layer of parallel graphene and uniformly distributed vertical graphene.

[0127] Figure 2 The images show the interface morphology of graphene and alumina in sintered graphene-reinforced alumina ceramics. Figure 2 As can be seen, the graphene at the interface is interwoven to form a rich 3D interlocking structure, which can strengthen the shear and tensile strength of the interface.

[0128] Figure 3 The figure shows the flexural strength test results of pure Al2O3 ceramic and G / Al2O3 ceramic after sintering. The flexural strengths of Al2O3 and G / Al2O3 ceramics are 264.13 MPa and 444.16 MPa, respectively. The flexural strength was increased by 68.16% by in-situ growth of vertical graphene on the surface of Al2O3.

[0129] Figure 4 The figure shows the fracture toughness test results of pure Al2O3 ceramic and G / Al2O3 ceramic after sintering. The fracture toughness of Al2O3 and G / Al2O3 ceramics are 3.49 MPa·m. 1 / 2 and 18.56 MPa·m 1 / 2 Vertical graphene was grown in situ on the surface of Al2O3 using CVD, which improved its fracture toughness by 431.81%.

[0130] Finally, it should be noted that this invention uses methanol as a precursor to grow graphene with a vertically distributed morphology in situ on ceramic powder, preparing graphene-ceramic powder with a uniform core-shell structure and a graphene encapsulation rate of over 60%. The graphene-ceramic powder is then collected and sintered to obtain a highly efficient and tough composite ceramic with a 3D interlocked graphene interface. This invention, by preparing graphene in situ on the surface of ceramic powder, firstly solves the inherent problems of graphene agglomeration and low coverage within the ceramic matrix; secondly, by controlling the growth process, vertical graphene can be prepared on the surface of ceramic powders of different sizes. Because vertical graphene has open atomic boundaries, it can covalently connect with each other after high-temperature sintering, thereby forming a 3D interlocked structure that efficiently strengthens the ceramic matrix, increasing the strength and fracture toughness of the ceramic by over 50% and 90%, respectively.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for developing 3D interlocked graphene interface-strengthened ceramics, characterized in that, include: A composite ceramic powder with vertically deposited graphene was obtained, and the composite ceramic powder with vertically deposited graphene was hot-pressed and sintered to obtain a 3D interlocked graphene interface with strong and tough composite ceramic. The process of obtaining composite ceramic powder with deposited vertical graphene is as follows: Using methanol (CH3OH) as a precursor, vertical graphene is grown in situ on the surface of ceramic powder by low-pressure chemical vapor deposition, achieving uniform and large-area coverage of graphene on the surface of ceramic powder, and obtaining composite ceramic powder with deposited vertical graphene.

2. The method for strengthening 3D interlocked graphene interface ceramics according to claim 1, characterized in that, Specifically, the following steps are included: The composite ceramic powder with deposited vertical graphene is pre-cooled and pressed in a graphite sleeve, then vacuum hot-pressed and sintered, and then cooled to room temperature in the furnace to obtain a 3D interlocked graphene interface strong composite ceramic.

3. The method for strengthening 3D interlocked graphene interface ceramics according to claim 2, characterized in that, The pre-cooling time is 10 min to 30 min; the cold pressing pressure is 20% to 50% of the hot pressing pressure.

4. The method for strengthening 3D interlocked graphene interface ceramics according to claim 2, characterized in that, The sintering temperature is 1550℃~2000℃, and the sintering time is 5min~2h.

5. The method for strengthening 3D interlocked graphene interface ceramics according to claim 2, characterized in that, The heating rate during the hot pressing process is 5℃ / min to 50℃ / min, and the hot pressing pressure is 20MPa to 80MPa.

6. The method for strengthening 3D interlocked graphene interface ceramics according to claim 1, characterized in that, The specific process for obtaining the composite ceramic powder with deposited vertical graphene is as follows: 1) Place the ceramic powder in the heat preservation area of ​​the chemical vapor deposition furnace, evacuate to a low-pressure atmosphere, and then heat it to 900℃~1200℃; 2) Introduce CH3OH to maintain the temperature and deposit graphene. After the deposition is completed, stop supplying CH3OH and cool down. Maintain a low-pressure atmosphere throughout the process to obtain composite ceramic powder with vertically deposited graphene.

7. The method for strengthening 3D interlocked graphene interface ceramics according to claim 6, characterized in that, In step 1), the ceramic powder has a spherical morphology and an average particle size of 0.1 μm to 20 μm.

8. The method for strengthening 3D interlocked graphene interface ceramics according to claim 6, characterized in that, The deposition time of graphene is 1h to 10h, and the deposition pressure is 8kPa to 20kPa.

9. The method for strengthening 3D interlocked graphene interface ceramics according to claim 6, characterized in that, The amount of powder fed during the deposition process is 1g to 15g.

Images